The switchable nanovalve for drug delivery that we cited three weeks ago is now one step closer to being tested in patients, although “further steps are required to demonstrate actual inhibition of tumor growth.” In these simple nanotechnology devices a molecule that changes shape when exposed to light lines the pores of a nanoparticle, expelling the drug carried by the nanoparticle. In a laboratory test, several types of human cancer cells were shown to take up the nanotech devices and were then killed when exposure to light released the drug from the nanoparticle into the surrounding cell. From the press release “UCLA researchers design nanomachine that kills cancer cells“:

Researchers from the Nano Machine Center at the California NanoSystems Institute at UCLA have developed a novel type of nanomachine that can capture and store anticancer drugs inside tiny pores and release them into cancer cells in response to light.

Known as a “nanoimpeller,” the device is the first light-powered nanomachine that operates inside a living cell, a development that has strong implications for cancer treatment.

…To achieve this, the UCLA researchers used mesoporous silica nanoparticles and coated the interiors of the pores with azobenzene, a chemical that can oscillate between two different conformations upon light exposure. Operation of the nanoimpeller was demonstrated using a variety of human cancer cells, including colon and pancreatic cancer cells. The nanoparticles were given to human cancer cells in vitro and taken up in the dark. When light was directed at the particles, the nanoimpeller mechanism took effect and released the contents.